Automatic train-control device



April 2, 1929.

T. H. THOMAS AUTOMATIC TRAIN CONTROL DEVICE Filed April-26. 1923 4 Sheets-Sheet l INVENTOR T HOMAS H. T HOMAS ATTORNEY April 2, 1929. T, H. THOMAS AUTOMATIC TRAIN CONTROL DEVICE 085 2. mm! MSR oh 051 uvPtm Put 2. 5 Ob Filed April 26, 1923 4 Sheets-Sheet INVENTOR THOMAS H.THOMAS B BY v 9/4 41. 0%% ATTORNEY April 2, 1929. 'r. H. THOMAS AUTOMATIC TRAIN cou'rnon DEVICE Filed April 26, 1923 4 Sheets-Sheet ATTORNEY INVENTOR THOMAS H .THOMAS BY MUN! 2 OLMI ouum April-2,-l 929. T. H. THOMAS 1,707,501 Afl'i'omnc Trina goN'rRoL DEVICE Filed April 26. 1923 4 sneets-shet 4 wul uzEF WNI 02:2:-

ATTORNEY INVENTOR 79 7 Oh M THOMAS HrrHoMAs i run ul I i h A w w w W IJ m fi. n v. I mmw mm .3 MW. r I

vention; Fig.2 asectional view of the main.

?atented Apr. 2, 1929.

'TEQMAS n. 'riionss, or nnenwoon, rensmva aq ssmmt fro 'riin wns'rino;

noose. AIR BRAKE oonnannjor nn/mamas, PENNSYLVANIA fA consona- V TION OF PENESYLVANIA.

- AUTOMATIC TRAIN-CONTROL DEVICE.

1 Application filed April 26', 1923. Serial No; 634,738. I

This invention relates to an automatic observed by the engineer in advance of the signal, then he must relyupon the. cab sig nal. The cab signalindication onlychanges as the signal is passedand it is then too late for the engineer to acknowledge the signal indication in order to prevent the automatic operation of the speed control equipment to reduce the speed of the, train to thelow speed limit.

' The principal object of my invention is to provide means for delaying the automatic o eration of the speedcontrol' equipment for a predetermined time, interval so that if the engineer acknowledges the signal indication within this time interval, the automatic opcration of the speed control equipment will be prevented.

in the accompanying drawings; Fig. I is a diagrammatic view otan automatic train speed control equipment embodying my1inspeed control valve mechanism of the equipment shown in Fig. 1, the partsbeing shown in high speed position; Fig. 3 a diagrammatre view, showing the manner in which the various elements of the speed control valve mechanism are charged. with fluid under pressure; Fig. 4i a diagrammatic view,'showing how certain parts of the'sp'eed control valve mechanism'are affected in case the engineer fails to acknowledge asignal indi-v cation; and Fig. 5 'a diagrammatic view, showing how certain parts of the speed control valve mechanism are affected in case the engineer acknowledges the signal indication within a predetermined time interval.

The automatic train speed control equip ment shown in the drawings is in many re-' spects, similar to the train speed control equipment shown in my prior Patent No. 1,523,462, issued January 20, .1925, and comprising a main valvemeohanisni 1, a speed;

governor valve mechanism 2, an engineer s brake' valve 3', an acknowledging valve4, a

main reservoir .5, an equalizing reservoir 6, a timing reservoir 7, a medium to low, speed blow. down reservoir 8,' a stopfreservoir 9, a high to medium speed blow down'reservoir 10, and an acknowledging valve reservoir The main valve mechanism 1 includes an application valve device Aryan equalizing discharge valve mechanism B,"a change speed valve device C, a selector valve device D, a mediumspeed valve device E, an acknowledging piston de.viceG,'a high speed magnet valve device H, a medium speed magnet valve device K, a high to'medium speed blow down .valve device L, a medium to low speed blow down valve device M, and a'feed valve device O. i s

The application valve device A. comprises apiston 12 'containedin piston chamber 13 and aslid e valve 14 contained in valve chamber .15. The equalizing discharge valve mechanism. B comprises a piston 16 having chamber 17 at one side connected by: passage and pipe 18 to equalizing reservoir 6 and chamber 19 atthe opposite side connected by passage QOto the brake pipe 21. A valve 110 operated by piston 16 controls the venting of. fluid under pressure from the'brake pipe 21to efl'ectan application of the brakes.

The change speed valve device C comprises differential pistons 22 and 23, the smaller piston 22 being contained in piston chamber 24 and the larger piston in piston chamber 25.. The valve chamber. 26 intermediate the pistons 22 and 23 contains; a slide valve 27 adapted to be operated by said pistons.

The selector valve device D comprises a piston 28 contained in piston chamber 29 and a slide'val-ve 30, contained in valve chamber 31-. The medium speed valve device E comprises a piston 32 contained in piston chamber 33 and a slide valve 34 contained in valve chamber 35.

The acknowledging valve device 4 comprises a casing'containing a rotary valve 36 and a handle 37for:operating said valve. The high speed magnet valve device comprises a magnet 38 and double beat valves '39 and 40 controlled by said'magnet and the medium speed magnet valve device K comprises a magnet 41 and double beat valves 42 and 43 controlled by said magnet.

The high to medium speed blow down valve device L comprises a valve piston 44 and valves 45 and 46 operable by said valve piston and the medium to low speed blow down valve device M comprises a valve piston 47 and valves 48 and 49 operable by said valve piston.

The acknowledging piston device G coinprises a piston 50 contained in piston chamber 51, a piston valve 52 and a poppet valve 53 operableby said piston. The speed governor valve mechanism comprises a speed governor P operatively connected so as to rotate at a speed proportional to the speed provided means for allowing a time interval. within which a signal indication may be ac-' knowledged by the engineer. The construction is preferably designed so that the time interval is allowed only when the change in the signal indication is from high speed to medium speed and comprises a valve mechanism which functions to delay, for a predetel-mined period of time, the movement of the change speed valve device from its high speed position to either its lower or its medium speed position, so that if during this time interval, the engineer acknowledges the signal indication as given in the cab, the change speed valve device will be shifted to its medium speed position, otherwise, if the engineer fails to acknowledge the signal indication during this time interval, the change speed valve device will be-shiifted to its low speed position.

For accomplishing the above purpose, a relay piston is provided, which is contained in a piston chamber 61 connected by pipe 62 to timing reservoir 7. T he piston (30 is adapted to operate a relay discharge valve 63 and also a charging valve 64'.

also provided a delay piston operate valves 66 and 67.

When the signal indication is for high.

There is speed, the electric control is such that the high speed magnet38 willbe energized and the medium speed magnet deenergized andthe parts Wlll be charged with fluid under pressure as follows: Fluid under pressure flows from the main reservoir 5 through pipe 69 and passage 70 to passage 71 and 65 adapted to thence through connecting passages to valve chamber 15 of valve device A, valve cham ber 26 of valve device C, valve chamber 31 of valve device D, valve 7 chamber 35 of valve device E and to feedvalve device S which then supplies fluid at a reduced pressure to charge the feed valve reservoir 72. The timing reservoir 7 is charged in the high speed position from the main reservoir through passage 7 2-3, past the open valve 40 of the high speed magnet valve device H to passage 7 4, and thence past the open valve 67 to a passage 76 leading to the timing reservoir pipe 62. V i

Vfhen the timing. reservoir 7 is charged with fluid under pressure, the relaypiston 60 operates to close the relay discharge valve 63 and open the charging valve 64, permitting fluid from the main reservoir to charge the piston chamber 25 of the change speed.

valve device C through passage 77, which communicates with passage 71, past the charging valve (34 to passage 7 8, passage 79 and through the acknowledging piston. de-

vice G- to iassage 80, cavity Si in slide valve 30 to passage 82 and thence to the p1ston chamber Tlhe other piston chamber 24 of the change speed valve device being supplied with fluid under pressure, from valve chamber 31 of the selector valve de vice D through passage 83, the change speed valve device will be maintained inits intermediate high speed position, as shown in Fig. 2. y v

l Vhen the signal. indication changes from high speed to medium speed, the high speed magnet 38 becomes deenergized and the me-- dium speed magnet 41 energized. The deenergization of the high speed magnet 218 causes the valve 40 to seat and the valve 39 to open, so that fluid under pressure will be vented from the timing reservoir 7 through passage 76, and thence through a restricted port 84 to passage 74, the check valve 75 preventing flow in that direction throughthe larger port opening. From passage 74 fluid is vented to exhaust port 85 past the valve 39.

In connection with the above operation it should be noted that there is also a direct communication from the passage 76 to the passage 74 which is controlled by the valve 67, therestricted port 84 being in a bypass v connection around said valve, but this direct communication is now closed by the valve 67 because the medium. speed magnet K being energized when a medium speed signal indication is received,'fluid from the main reser voir 5 is supplied to the delay piston 65 through passage 93, past the open valve 43 to passa e 94 which leads to the piston chamber at the face oi piston 65. The pis ton 65 is therefore operated to seat the valve 67. It will thus be seen that it requires a certain time interval for the pres sure in the timing reservoir 7 to reduce by llil iae a eoi li'oi'v' through the restricted port 84 and until the preset-ire If the englneerfails to acknowledge the indication, the acknowled ing piston 50 will remain in its position, establishing coinmurjiication from pistonchamb'er 25 to passage 78; by Way oil passage 82, cavity 81 in slide valve 30, passage 80, and past the open valve 52 to passage 79, that when the pressure in the timing reserv' 7 has been reduced to predetermined. degree by flow through the restricted port 2% and out at the exhaust port 85, the pistonfill will move toclose the valve Gel and open valve $3,- permittlng the venting of fluid from piston chamber 25 tlni-ough passage 7 8- and past the open valve 63'. to the atmosphere. The

change speed valve device Will then be shifted to its low speed position, so that the speed control mechanism will then operate to reduce the speed of-lhe train to. the low speed limit.- scr-ibed Where the signal indication changes from high speed to medium speedand the signal indication is not acknowledged is shown d'ia raminatically in Fig;

If the signal indication changes from high speed to medium speed and the engineer acknowledges the signal indication by moving the acknowledging valve to its acknowledging position during the time interval in which the pressurein the timing reservoir? is being; reduced fluid under pressiire will be supplied to the acknowledging piston 50 from the acknowledging reservoir 11, through pipe96, passage 97, cavity 98 in slide valve 14:, and the piston 50' will thenbe shifted so to cause the valve 52 to cut off communication from passage 79 to passage 80 and consequently When the piston 60' moves downwardly upon depletion of the fluid pressure in thetiming reservoir "7, although the discharge valve 63 will be opened, fluid under pressure Will not be vented from the piston. chamber 25 of the change speed valve device .0. y

The movement of the acknowledging piston 50, however, operates to open the valve so that fluid under pressure is vested from piston chamber 29 of the selector valve device D through passage 86, past the open valve to passage 79 and thence to the atmosphere through passage 78, past the open valve 63. The selector p1st0n28 Will then be shifted to its outer position, thereby .moving the slide valve 30 so as to cut off communication from the piston chamber of the change speed valve device C to the passage 80.

The movementof the selector piston 28 and slide valve to the outer position results in establishing communication from in the timing reservoir '7 has been reduced to predetermined degree, the relay piston Will remain in its upper -position.

The operation above do the spring side of the high to medium. bio-w down valve piston 45 and also the high to medium reservoir 10 to the blow down ti1ningeiihaus't as controlled by the speed governor valve mechanism 2 byway of passages 87 and 88, cavity 89 slide'valve and passage 99-, which is'conhec'ted by pipe 91 to the speed governor valve meehanismf When-the pressure in the reservoir 10 and at the spri g side of the. valve piston 45 has been r'educedto a predetermined degree, the

valve piston is operated to open valve 46 so that-fluid under pressu'reis ventedfroin vpiston chamber 24L- of the change speed valve device C to the atmosphere of passage 83, past the open valve 46 to exhaust port 92. The change speed valve device C Will then be shifted to its medium speed positiornfas shown in the diagram Fig. 5. In the medium speed position of the change" speed valve device C, the. piston chamber the speed governor P, so that if the speed of the train exceeds 'the medium speed limit,

fluid Will be vented from piston chamber: 13 of the application valve deviceand said valve device Willthen be operated to effectan application of the brakes.

"The tmiing'mterval provided as hereinbefore described, Within which the engineer may acknowledge a change in the signal indication Without being subjected to the penalty of having" the speed limit of the train reduced to lovispeed limit is not desirable in case the signal I indication changes from highspeed to low speedinstead of from high speed to mediumspeed,

due for example, to a train on a side track entering the main track,since in such event,

of passage 93, past the open valve 48, and

passage 94;. The piston is then operated to close the valve 67 Which closes a large port- Connection from'passage 76 topassage 74 and the venting of fluid from the timing reservoir is limited to a rate as determined by the restricted port 84%, so that the desire time interval is provided.

1 13 of the application valve device A is con- 7 nected to one'of the'valves controlled by.

When the sio'oal indication changes from I u bo 1 high speed directly to low speed, the medium speed magnet 4-1 remainsdeenergized, as it was when the signal indication was at high zit) speed, so that the valve leis held closed While the valve 42 is held open. The piston 65 is consequently 03GB to the atmosphere by Way of passage 9%, past the open valve 42 to exhaust port 95 and valve 57 will re main in its open position.

Fluid under pressure Will. then be vented from the timing reservoir 7 at a rapid rate by Way of passage 76, past the open valve 6? to passage 7% and thence past the open valve 39 controlled by the high speed magnet 38 to the exhaust port 85. The pressure in the timing reservoir 7 is thus quickly reduced and consequently the piston 60 is quickly operated to open the valve 63, so that substantially no time interval elapses before the change speed valve device C is operated by the venting; of fluid pressure from piston chamber 25, so that said change speec valve device promptly moves to its low speed position. j

The object of the charging valve 6st is to provide means for charging the piston chamber of the change speed valve device Cu'heu the signal indication changes l rom loW speed to l'iigh speed, so that the change speed valve device will be shifted to its high speed position. l l hen the signal indication changes to high speed, the high speed magnet 88 becomes energized, so that fluid under pressure is supplied by the opening of valve 40 to the timing reservoir 7 and piston chamber (ll of the relay piston 60. Upon restoration of fluid pressure, the pisten is operated to close the valve 63 and open the charging valve G l, so that fluid under pressure is supplied to the piston chamber 25 of the change speed valve device C from passage 79, past the open valve 64 to passage 78 and thence through passa 79, passage 80, cavity 81 in slide valve and passage 82 to piston chamber 25. 1.1 increase in pressure in piston chamber 20 will then operate to retin'n the change s Jeed valve device C to its high speed position.

On account of the relatively small volume of the piston chamber 13 of the application valve device A, it has been found that there K (D u vis a possibility that the application piston may niiove to application position when not intended, through the creation of a slight differential pressure, due to possible leakage in the pipes and passages connected to said chamber and in order to avoid this possibility, another feature of my invention consists in providing an ill')].)ll(fll;l011 reservoir 100, the volume oi? which is connected to the application piston chamber 13 by way of pipe 101, iassage 10:2, and passages 103 and 104i.

The reservoir 100 may be charged from the main reservoir 5 through a pipe 105 contain ing a choke fitting 106 having; a restricted port through which fluid under pressure is supplied to said reservoir and the pipe 101 may be provided With a check villi e107 for preventing back l'lOW from the piston chamber 13 to the reservoir 100. 7

Having now described my invention, What I claim as new and desire to secure by Letters Patent, is

1. In a train speed control apparatus, the combination with valve means responsive to a change in the signal indicationlordetermining the speed limit of the train, of means for delaying the operation of said valve means alter he signal indication is received and independently of the speed of the train,

for a definite and substantial period of time v and sufiicient to permit the engineer to act. 2. In a tram speed control apparatus, the

combination With 'valve means responsive to a change in the signal indication for deter mining the speed limit of the tram, of means for delaying the operation of said valve means after the signal indication is received insrval after receiving a signal indication to proviee a time 1 erval Within which the engineer may act after receiving the signal indication.

In a train speed control apparatus, the ccn'ibination with a valve device movable upon a change in the signal indication to a position for effecting a change in the speed limit of the trainer means for delaying the movement of said valve device for an eX tended predetermined time interval which is independent of the. speed of the train.

5. ln. train speed control apparatus, the combination with a mechanism having a tendency to move to a position for effecting a change in the speed limit of the train due to a change in the signal indication, of means for delaying the operation of said valve device i501 a 'ircdetermined time interval and means operable by the engineer during said time interval for etfectii the movement ol said mechanism toanoth -r position in which said mechanism is ell'cctivc to ii a diili erent train speed limit.

6. train speed control apparatus. the combination Witn a valve device operative to thespeedlimit ol' the train and having high, medium, and low speed limit posiions and means operative upon a change in he 'gnal indication from high speed to nedium speed for ellecting the movement oi 1 Salt.

valve device to its low speed position CIK piston operative to determine the speed lim t oid means a: d aying th opera ic-ap said va v lev ce tor n'ecl e medtu e interval.

7 In a train speed control apparatnsfthe combination with a valve device having a piston subject to fluid under pressure operative to determine the speed limited ,the train, of .a timing reservoir normally charged with fluid under pressure a valve device .0 1-

r tion inpr a u e in said erative upon a r a i 9' fluid from sa d piston,

reservoir for yen subject to fluid under pressure and the train, of timing reservoir no mal y charged with fluid under ,pnessnraa valve device operatiue upon a reduction inpres;

surein said reservoir i'ior venting fluid from said piston, means responsiveto a change in the ndication vent-ingjfiuld 0 th p essur th m from said reservoir, and means under the control of the engineer for controlling loommunication through avhichrfiuid' is vented from said piston.

9. In a train speed control apparatus, the

combination with a valve device movable to difierent positions for fixing the speed limit of the train and having pistons normally subject to fluid under pressure, of a timing reservoir normally charged with fluid under pressure, a valve device operated upon a re duction in pressure in said reservoir for venting fluid under pressure from one piston, a valve mechanism movable to a posi tion for venting fluid under'pressure from the other piston, means responsive to a change in the signal indication for venting fluid from said reservoir, and means operable by the engineer for effecting the opera tion of said valve mechanism.

10. In a train speed control apparatus, the combinatirm with valve means responsive to a change in the signal indication from high speed to medium speed or from high speed to low speed for fixing the speed limit oi the train, of means for delaying the operation of said valve means for a time interval'when the signal indication changes from high speed to medium speed and means for permitting the operation of said valve means without delay when the signal indication changes from high speed to low speed.

11. In a train speed control apparatus, the combination with valve means responsive to a change in the signal indication for fixing the speed limit of the train,'of a timing reservoir normally charged with fluid under pressure, a valve device operated upon a, predetermined reduction in pressure in said reservoir for eiiecting the operation of said valve means and means controlled by a mining the mite/e12 Win 1? a cha ge in the ignal in ica ion l g ifluicl om said mserve r fr m rese voir- 1 a l2, In a speed ,controha-pparatus, the combination with valve @eansgresponsive to a chang v n the s gnal in icationfor fixing thespeed lim 3 th train, of nt m g reservoir normally charged with fluicl under pressure, a valve device operated upon a p determined irredu ion in Pressur i said reserv r t r fie t ng t e neratien at d va ei.,means a d means pane e m hi speed to median; speed for venting ,fiu d change E hQ SigQQJ ind a on for en d for d eters id is ve t d from said reserv at a restricted rate and v upon ch nge 1;. e sign induc ion from igh spee t 1. 9 i, p ed. fo vent g f d om ad rearv i at a m re rapi 1;. 1 1-, a n speed-control piper... S, lik combination with a change speed valve dec having a p ate norm lly su jec t 0i .a tim ng l ss 1:, mg a nstonu u. teat ,zeaerva a d fluid tinder pm a a e mechanism ative upen placat fluid under pressure from thepiston of the change speed valve device and magnet controlled valve means operative upon a change from said timing reservoir.

li reduc ien' 1 a pressu e said neser vo r torvent ng .14. In a train speed control apparatus, the

combination with an application valve device having an operating piston contalned in a piston chamber normally charged with.

fluid under pressure, of a volumereservoir connected to said piston chamber and means for effecting a rapid recharge of only the;

piston chamber, following a reduction in pressure in sa d chamber and said reservoir. I l5QIn a train speed controlapparatus, the

combination with an application valve de vice having an operating piston contained in a piston chamber normally charged with fluid under pressure, of a volume reservoir connectedto said piston chamber, means for charging said reservoir through a re- I stricted port, and a check valve for preventing back flow from sald piston chamber'to said reservolr to perm1t a rapid recharge of the piston chamber following a reduction in pressure therein. 7

16. In a train speed control apparatus, the combination wlth a change speed valve clevice having an operating piston contained in a piston chamber, of a timing reservoir normally charged with-:fiuid under pressure, valve means for controlling the ad mission and release of fluid under pressure to and from sa1d plston chamber, and aplston sub ect to the pressure 1n said timing reservoir for controlling the operation of said valve means.

17 In a train speed control apparatus, the

combination with a change speed valve device having an operating piston contained in a piston chamber,'of a timing reservoir normally charged with fluid under pressure,

T a valve for venting fluid under pressure from said piston chamber, a valve for supplying fluid under pressure to said'chamber, and a piston subject to the pressure in said reservoir for controlling the operation of said valves.

18. In a train speed control apparatus, the combination with means responsive to a change in the signal indication for determining the speed limit of the train, oi": means for delaying the operation of said signal indication responsive means for a time interval after the signal indication is received and independently ofthe speed of the train, said time interval being of substantial .duration such as to permit action by the engineerQ 19. In a train'control apparatus, the com bination with an application, valve device having an operating piston contained in a piston chamber and means operated by said piston upon a reduction in fluid pressure in said chamber for effecting an application through an always open restricted port and connected at all times to said piston chamber through a relativelyunrestricted communication whereby the flow of fluid from the reservoir to the piston chamber is at a greater rate than the flow of fluid from the source of pressure to the reservoir.

20. In a train control apparatus, the combination with a main reservoir, of an application valve device having an operating piston contained in piston chamber and means operated by said piston upon a reduction in fluid pressure in said chamber for effecting an application of the brakes and a volume reservoir charged f1OII1,'i3l1O main reservoir through a rest icted port and connected to said piston chamber through an always open communication such that fluid under pressure will flow from the reservoir to the piston chamber at a greater rate than fluid under pressure can flow from the main reservoir to said volume reservoir.

In testimony whereof I have hereunto set my hand. 7 vTHOMAS H. THOMAS. 

